Gas analyzer having a test chamber traversed by radiation

Abstract

In the gas analyzer described in the specification, a test chamber housing for accommodating a volume of gas to be analyzed has a spherical shape and a spherical inner mirrored surface with windows to receive a radiation beam from a source and pass the beam to a detector. To provide different test distances through the chamber for the radiation beam, the source of radiation and the housing are movable relative to each other so that a reproducible change in the test distance can be achieved through multiple reflections on the inner mirrored surface of the housing.

I claim: 
     
       1. A gas analyzer comprising a radiation source, a radiation detector, a test chamber of spherical configuration to receive gas to be analyzed including an inner housing surface of spherical configuration and having entrance and exit windows for receiving radiation emitted by the radiation source and passing radiation to the detector, respectively, a mirror surface of constant curvature extending over substantially the entire inner housing surface wherein the radiation attenuation in the gas measured by the detector may be used to characterize the gas in the test chamber, and support means for providing positioning adjustment between the test chamber and one of the source and the detector in order to vary the test distance. 
     
     
       2. A gas analyzer according to claim 1, wherein the mirror surface is the inner housing surface. 
     
     
       3. A gas analyzer according to claim 1 or claim 2, wherein the support means comprises a cardanic suspension having a plurality of step motors for providing relative motion between the test chamber and one of the source and the detector.